Brain Shunt

Nov. 14, 2025

This page was reviewed under our medical and editorial policy by Keng Lam, M.D., assistant clinical professor, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte.

Some patients with brain tumors can experience a potentially dangerous buildup of cerebrospinal fluid in the brain. Cerebrospinal fluid is a substance produced in the brain that surrounds and protects both the brain and spinal cord.

A buildup of cerebrospinal fluid can cause swelling that puts pressure on the brain, leading to damage to brain tissue. One way to treat this condition is to surgically place a shunt into the brain. A brain shunt channels the excess cerebrospinal fluid away from the brain to reduce the swelling.

What Is a Shunt?

A brain shunt is a small, hollow tube that’s placed inside the brain to help relieve a buildup of cerebrospinal fluid. A buildup of fluid in the brain (also called hydrocephalus) is a common side effect of brain tumors and occurs when a tumor blocks the normal flow of cerebrospinal fluid through the brain.

Hydrocephalus may cause symptoms ranging from changes in vision to persistent headaches. In most cases, a brain shunt is placed in an area of the brain called the lateral ventricles, which are cavities in the brain that help produce cerebrospinal fluid

Brain Shunt vs Ommaya Reservoir

Another procedure that’s sometimes used in treating brain tumors is the placement of an Ommaya reservoir – a device that’s placed in the ventricles and collects cerebrospinal fluid. An Ommaya reservoir may be used to take samples of cerebrospinal fluid for analysis or to deliver medication directly to the brain.

Types of Shunt Valves

Brain shunts usually use a valve system to make sure that excess cerebrospinal fluid is sent away from the brain and to control how much fluid is drained. There are two main types of valves used with brain shunts.

• A fixed shunt valve begins to drain fluid away from the brain only once the amount of fluid in the brain reaches a certain fixed threshold.
• An adjustable shunt valve can be adjusted to allow more or less fluid to drain away from the brain as necessary.

Determining which type of shunt valve to use to treat hydrocephalus caused by a brain tumor depends on a number of factors, including the type of tumor a patient has, what part of the brain where it’s located and the patient’s overall health.

Shunting Systems

There are several different shunting systems that may be used with a brain shunt. The term shunting system refers to the way in which a brain shut moves cerebrospinal fluid from the brain to another part of the body.

• Ventriculoperitoneal (VP) shunting systems move fluid from the brain into the peritoneum, which is the cavity in the abdomen where many of the body’s organs are.
• Ventriculoatrial (VA) shunting systems move fluid from the brain into a vein in the neck that flows into the a part of the heart called the atrium.
• Ventriculopleural (VPL) shunting systems move fluid from the brain to the space between the chest and the lungs, which is called the pleural cavity.
• Lumboperitoneal (LP) shunting systems move fluid from the spinal cord to the peritoneum.

Shunt Procedure

The surgery to place a brain shunt is performed by neurosurgeons with expertise in operating on the brain and spinal cord. Patients receive general anesthesia and are asleep for the procedure. During brain shunt surgery:

• Surgeons open the skull and guide a thin, narrow tube called a catheter to the lateral ventricles, where it is placed.
• This tube is attached at the other end to the shunt valve, which is usually placed beneath the skin just above the ear.
• The shunt valve is then attached to another catheter tube, which is placed under the skin and runs from the valve to the area of the body where the shunting system will drain the cerebrospinal fluid.

After brain shunt surgery, most patients recover in the hospital for several days.

Living with a Brain Shunt

Brain shunts are a potentially life-saving way to treat and manage hydrocephalus. They also play a key role in helping manage fluid buildup that can be caused by brain tumors. However, many patients who undergo brain shunt surgery have questions about how the procedure might affect their day-to-day life. Here are the answers to some common questions and concerns.

Is a brain shunt permanent?

For most people, a brain shunt is a permanent treatment option for hydrocephalus.

Will a brain shunt need to be replaced?

In about 6 out of 10 cases, a brain shunt does not need to be replaced. However, for around 40% of patients, a brain shunt may fail or stop working properly and need to be replaced. Patients with a brain shunt must have routine checkups with their neurosurgeon to ensure their brain shunt is working properly.

Is a brain shunt visible?

No – a brain shunt is placed inside the brain and the tubing that connects it to another part of the body is usually placed beneath the hair and skin, which means it is not visible outside the body.

How do you know a brain shunt is working?

It is not always possible to know for sure that a brain shunt is working. Patients who experience any issues that suggest their brain shunt may not be working properly should contact their care team or neurosurgeon for help.